CN114962507B

CN114962507B - Automobile drum brake

Info

Publication number: CN114962507B
Application number: CN202210613793.9A
Authority: CN
Inventors: 刘成晔; 韩聪
Original assignee: Jiangsu University of Technology
Current assignee: Jiangsu University of Technology
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2023-09-22
Anticipated expiration: 2042-05-31
Also published as: CN114962507A

Abstract

The invention discloses an automobile drum brake, comprising: a fixed plate; the alarm is fixedly arranged on the fixed disc; the four shoe blocks are respectively connected to one end of the fixed disc in a rotating way through fixed pin shafts; the support piece is fixedly connected to the outer sides of the outer walls of the two hoofs; the friction plates are fixedly arranged on the outer wall of the supporting plate; the fixed seat is fixedly arranged on the fixed disc; and the connecting shaft penetrates through the fixed seat, and two ends of the connecting shaft respectively extend to the space between the two groups of shoe irons and the outer side of the fixed disc. This car drum brake has multiple degree warning effect, and overall structure sets up rationally, and warning effect reliability is high, further plays the effect that improves the backing plate fastness at friction braking's in-process, improves the structural stability and the heat dispersion of whole brake drum, guarantees its life.

Description

Automobile drum brake

Technical Field

The invention relates to the technical field of brakes, in particular to an automobile drum brake.

Background

The brake is a device with the functions of decelerating, stopping or keeping a moving part (or moving machine) in a stopping state, is a mechanical part for stopping or decelerating the moving part in the machine, is commonly called a brake and a brake, mainly comprises a brake frame, a brake part, an operating device and the like, is also provided with an automatic adjusting device for the gap of the brake part, is usually arranged on a high-speed shaft of equipment for reducing braking moment and structural size, and is arranged on a low-speed shaft close to the working part of the equipment for large-sized equipment (such as a mine hoist, an elevator and the like) with higher safety requirements;

at present, the types of automobile brakes are more, and the drum brake uses a brake transmission mechanism to enable a brake shoe to compress a brake friction plate on the inner side of a brake drum, so that braking force is generated, wheels are decelerated or stopped in the shortest distance according to requirements, driving safety is ensured, the automobile is ensured to be parked reliably and cannot automatically slide, when the abrasion of a shoe reaches a limit position, the whole braking performance of the brake is greatly reduced, even the situation of braking failure occurs, but a driver cannot sense the abrasion state of the brake, and a certain potential safety hazard exists.

Disclosure of Invention

The invention aims to provide an automobile drum brake, which at least solves the problems that when the abrasion of a shoe reaches the limit position, the whole braking performance of the brake is greatly reduced and even the brake fails. However, the driver cannot sense the wearing state of the brake, and the problem of certain potential safety hazard exists.

In order to achieve the above purpose, the present invention provides the following technical solutions: an automotive drum brake comprising:

a fixed plate;

the alarm is fixedly arranged on the fixed disc;

the four shoe blocks are respectively connected to one end of the fixed disc in a rotating way through fixed pin shafts;

the support piece is fixedly connected to the outer sides of the outer walls of the two hoofs;

the friction plates are fixedly arranged on the outer wall of the supporting plate;

the fixed seat is fixedly arranged on the fixed disc;

the connecting shaft penetrates through the fixing seat, and two ends of the connecting shaft extend to the space between the two groups of hooves and the outer side of the fixing disc respectively;

the driving block is fixedly connected to one end of the connecting shaft and is positioned between the two groups of shoe irons;

the roller is arranged between the two shoe irons in a way of rotating around the axis of the roller and is tightly contacted with the outer wall of the driving block;

the stop mechanism is fixedly arranged between the two shoe irons;

and the brake bottom plate is sleeved on the outer sides of the friction plates.

In a possible embodiment, the automotive drum brake further comprises: the connecting piece is fixedly sleeved at the other end of the connecting shaft; the hinged support is rotatably connected to the other end of the connecting piece; and the air cylinder is connected with the hinged support through the output end of the air cylinder.

In a possible implementation mode, the supporting plate and the hoofs are further provided with reinforcing plates and reinforcing strips, a plurality of reinforcing plates are respectively and fixedly connected in gaps between the two hoofs, the reinforcing plates are fixedly connected with the supporting plate, and a plurality of reinforcing strips are fixedly arranged on the inner wall of the supporting plate and are perpendicular to the direction of the reinforcing plates.

In one possible embodiment, the stop mechanism comprises: the extension seat is fixedly arranged between the two shoe irons and is positioned at the far side of the fixed pin shaft; the two stop pieces are integrally formed at the inner edge position of the fixed disc; the driving assembly is connected below the extension seat.

In one possible embodiment, the drive assembly comprises: the fixed column is fixedly connected below the extension seat; the two sleeve pieces are fixedly arranged at the upper end and the lower end of the inner cavity of the fixed column; the bending cavity is arranged at one side between the two sleeve pieces; the bending piece is movably arranged in a gap between the two sleeve pieces; the driving column is fixedly penetrated through the bending sheet, two ends of the driving column are located on the outer side of the fixing column, and two ends of the driving column are respectively a stress end and a driving end.

In one possible embodiment, the drive assembly further comprises: a plurality of first springs are arranged in the inner cavity of the fixed column and positioned at the driving end side of the driving column; the clamping block is movably clamped in the inner cavity of the fixed column, and the outer wall of the clamping block is in close contact with the first spring; the clamping grooves are formed in the outer wall of the driving column, and the clamping grooves correspond to the clamping blocks in position and shape.

In a possible embodiment, the alarm comprises: the positioning plate is fixedly arranged on the inner side of the fixed disc and is positioned on the far side of the fixed pin shaft; the alarm shell is fixedly arranged on the positioning plate; the two moving parts are movably arranged in the inner cavity of the alarm shell; the two lugs are fixedly arranged on two sides of the outer wall of the moving part and are clamped in the slideway of the alarm shell, and the two adjacent lugs are electrically connected; the separation block is fixedly arranged in the middle of the inner cavity of the alarm shell; the contacts are respectively arranged on the inner wall of the alarm shell; and the second spring is arranged between the separation block and the moving piece.

In one possible embodiment, the outer end of the moving member extends to the outside of the alarm housing and corresponds to the movement track of the fixed column.

In one possible embodiment, the reinforcing plate is made of a thermally conductive material.

In one possible embodiment, the bending sheet is an alloy memory metal material.

The automobile drum brake provided by the invention has the beneficial effects that:

1. in the actual use process, the friction force between the friction plate and the braking bottom plate is pushed mainly through the rotation of the shoe to realize the braking effect, but the friction plate is used as a vulnerable braking part, and is one of parts which need to be replaced regularly in the whole system, so the device is also provided with an alarm, the loss degree of the friction plate is perceived through the alarm, the alarm adopts a mechanical structure to realize the alarm function, the alarm has various degrees of alarm effects, the whole structure is reasonable to set, and the reliability of the alarm effect is high.

2. According to the invention, the connecting effect between the two hooves can be firmer through the arrangement of the plurality of reinforcing plates, the stability among the supporting plates, the friction plates and the whole hooves is stronger, a more reliable braking effect can be achieved in the friction braking process, the firm degree of the supporting plates is increased through the arrangement of the reinforcing strips, the situation that the stress is abnormal and even breaks after the whole supporting plates are braked is avoided through the scheme of being perpendicular to the direction of the reinforcing plates, and the effect of improving the firmness of the supporting plates is further achieved in the friction braking process.

3. The invention is provided with a plurality of contacts, when the friction plate is worn to different degrees, the contacts at different positions are communicated through the lug on the moving part, so that the alarm can send out different alarm signals, wherein the contact at the middle part of the alarm shell is communicated with the alarm circuit signal generating interface with the most serious alarm, and the contact represents that the wear degree of the current friction plate reaches the limit state.

4. The reinforcing plate is made of the heat conducting material, so that heat generated in the braking process of the friction plate can be conducted out through the reinforcing plate, the structural stability and the heat dissipation performance of the integral brake drum are improved, and the service life of the integral brake drum is ensured.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

FIG. 2 is a schematic view of the structure of the reinforcing plate according to the present invention;

FIG. 3 is a schematic diagram of a driving assembly according to the present invention;

FIG. 4 is a schematic view of a partial cross-sectional structure of an alarm of the present invention;

fig. 5 is an enlarged view at a in fig. 2.

In the figure: 1. the brake disc comprises a fixed disc, 2, an alarm, 3, a shoe, 4, a supporting sheet, 5, a friction sheet, 6, a fixed seat, 7, a connecting shaft, 8, a driving block, 9, a roller, 10, a connecting piece, 11, a hinge support, 12, an output shaft, 13, a cylinder, 14, a brake bottom plate, 15, a fixed pin, 16, a reinforcing plate, 17, a reinforcing strip, 18, an extension seat, 19, a stop piece, 20, a driving component, 201, a fixed column, 202, a sleeve, 203, a bending cavity, 204, a bending sheet, 205, a driving column, 206, a first spring, 207, a clamping block, 208, a clamping groove, 21, a positioning plate, 22, an alarm shell, 23, a moving piece, 24, a bump, 25, a separation block, 26, a contact, 27 and a second spring.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1 to 5, the present invention provides a technical solution: an automotive drum brake comprising: the brake device comprises a fixed disc 1, an alarm 2, hooves 3, supporting plates 4, friction plates 5, a fixed seat 6, a connecting shaft 7, a driving block 8, rollers 9, a stop mechanism and a brake bottom plate 14, wherein the alarm 2 is fixedly arranged on the fixed disc 1, every two of the four hooves 3 are respectively connected to one end of the fixed disc 1 through a fixed pin shaft 15 in a rotating mode, the supporting plates 4 are fixedly connected to the outer sides of the outer walls of the two connected hooves 3, a plurality of friction plates 5 are fixedly arranged on the outer walls of the supporting plates 4, the fixed seat 6 is fixedly arranged on the fixed disc 1, the connecting shaft 7 penetrates through the fixed seat 6, two ends of the connecting shaft extend to the space between the two groups of hooves 3 and the outer side of the fixed disc 1 respectively, the driving block 8 is fixedly connected to one end of the connecting shaft 7 and is positioned between the two groups of hooves 3, the rollers 9 can be arranged between the two hooves 3 in a rotating mode around the axis of the self, the stop mechanism is fixedly arranged between the two hooves 3 and is in tight contact with the outer walls of the driving block 8, and the brake bottom plate 14 is sleeved on the outer sides of the friction plates 5.

It should be noted that, this scheme mainly promotes frictional force between friction disc 5 and the brake bottom plate 14 through the rotation of shoe 3 and realizes braking effect in the in-service use, but friction disc 5 is as a vulnerable brake piece, is one of the spare part that needs periodic replacement in the overall system, consequently this device still is provided with alarm 2, through the loss degree of alarm 2 perception friction disc 5, adopts mechanical type's structure to realize alarming function in the alarm 2, and has multiple degree alarming effect, and overall structure sets up rationally, and alarming effect reliability is high.

The alarm 2 can be a device with simple alarm signal transmission, after the power is turned on, the alarm 2 automatically sends out an alarm signal, and the alarm 2 can be electrically connected with the whole vehicle controller, so that after the alarm 2 detects that a brake pad reaches a specified wear degree, the brake pad is displayed by a control instrument panel of the whole vehicle controller, so that the effect of reminding a driver is achieved.

Still further, the automotive drum brake further comprises: the connecting piece 10, the hinge support 11 and the cylinder 13, the connecting piece 10 is fixedly sleeved at the other end of the connecting shaft 7, the hinge support 11 is rotatably connected at the other end of the connecting piece 10, and the cylinder 13 is connected with the hinge support 11 through the output end thereof.

It can be understood that the device drives the rotation of the plurality of shoes 3 through the connecting piece 10, the hinged support 11 and the air cylinder 13, and pushes the plurality of friction plates 5 on the outer side of the device to contact with the brake bottom plate 14, when a driver steps on the brake pedal, the air cylinder 13 is started and the output end of the controller moves outwards, simultaneously pushes the connecting piece 10 to rotate, drives the integral connecting shaft 7 to rotate through the rotation of the connecting piece 10, drives the driving block 8 to rotate, and pushes the two groups of iron shoes to rotate through the cam-shaped driving block 8 after the rotation under the action of the cam shape of the driving block 8, so that the rotating effect of the two groups of iron shoes is realized, and the supporting plate 4 and the friction plates 5 are controlled to synchronously move outwards and are in friction braking with the brake bottom plate 14.

Furthermore, the supporting plate 4 and the shoe 3 are further provided with a reinforcing plate 16 and reinforcing strips 17, the reinforcing plates 16 are respectively and fixedly connected in the gaps between the two shoes 3, the reinforcing plates 16 are fixedly connected with the supporting plate 4, and the reinforcing strips 17 are fixedly arranged on the inner wall of the supporting plate 4 and are perpendicular to the direction of the reinforcing plates 16.

It can be appreciated that the arrangement of the plurality of reinforcing plates 16 can make the connection effect between the two shoes 3 firmer, and similarly, the stability between the supporting plate 4, the friction plate 5 and the whole shoes 3 is stronger, and the friction braking process can play a more reliable braking effect, the arrangement of the reinforcing strips 17 increases the firmness of the supporting plate 4, and the scheme of the vertical arrangement of the reinforcing plates 1616 can avoid the situation that the stress is abnormal or even broken after the whole supporting plate 4 is braked, and the effect of improving the firmness of the supporting plate 4 is also played in the friction braking process.

Still further, the stop mechanism includes: the extension seat 18, the stop piece 19 and the driving component 20, the extension seat 18 is fixedly arranged between the two hooves 3 and is positioned on the far side of the fixed pin shaft 15, the two stop pieces 19 are integrally formed at the inner side edge position of the fixed disc 1, and the driving component 20 is connected below the extension seat 18.

It will be appreciated that the extension seat 18 is fixedly disposed between the two shoes 3, a portion of the extension seat 18 extends to the outer side of the shoes 3, wherein the extension member and the driving assembly 20 are fixedly connected to the shoes 3, the shoes 3 rotate during braking, the extension member and the driving assembly 20 rotate at the same time, the driving assembly 20 during rotation impacts the stop 19, the external shape of the driving assembly 20 after impact changes, the shoes 3 recover to the initial position after the vehicle is released from braking, and the deformed driving assembly 20 drives the alarm 2, thereby realizing the basic alarm effect.

Still further, the driving assembly 20 includes: the fixing column 201, the sleeve 202, the bending cavity 203, the bending piece 204 and the driving column 205, wherein the fixing column 201 is fixedly connected below the extension seat 18, the two sleeve 202 are fixedly arranged at the upper end and the lower end of the inner cavity of the fixing column 201, the bending cavity 203 is arranged on one side between the two sleeve 202, the bending piece 204 is movably arranged in a gap between the two sleeve 202, the driving column 205 is fixedly penetrated through the bending piece 204, the two ends of the driving column 205 are respectively provided with a stress end and a driving end.

Specifically, the fixed column 201 is fixedly connected to the lower part of the extension piece, in the braking process, the fixed column moves synchronously with the shoe 3, the driving column 205 on the inner side of the fixed column moves synchronously, when the friction plate 5 moves seriously and is worn, the whole shoe 3 can only rotate by a larger amplitude to ensure the braking effect, when the rotation amplitude of the shoe 3 is amplified, the moving stroke of the driving column 205 also changes, the fixed column is reloaded with the stop piece 19, the stop piece 19 pushes the whole driving column 205 out of one end distance in the direction opposite to the movement of the whole driving column, the length of the stressed end on the driving column 205 is reduced, the length of the driving end is increased, after a driver releases a brake pedal, the shoe 3 is restored to the initial position, and in the movement process, the driving end of the overlong driving column 205 pushes the alarm 2 to give an alarm.

Still further, the driving assembly 20 further includes: the clamping device comprises a first spring 206, clamping blocks 207 and clamping grooves 208, wherein a plurality of first springs 206 are arranged in an inner cavity of a fixed column 201 and are positioned at the driving end side of a driving column 205, the clamping blocks 207 are movably clamped in the inner cavity of the fixed column 201, the outer walls of the clamping blocks 207 are tightly contacted with the first springs 206, the clamping grooves 208 are formed in the outer walls of the driving column 205, and the clamping grooves 208 correspond to the clamping blocks 207 in position and shape.

It can be understood that, in order to prevent the driving end of the driving column 205 from being stressed, the length of the stressed end is reduced, so that a clamping block 207 is further arranged in the inner cavity of the driving column 205, and the limit effect of the whole driving column 205 is further ensured by matching the clamping block 207 with the groove of the inclined surface, so that the length of the driving end in the limit column can only be increased, and the thickness of the friction plate 5 can only be thinned correspondingly, thereby ensuring the accuracy of an alarm result.

Still further, the alarm 2 includes: the positioning plate 21, the alarm shell 22, the moving parts 23, the protruding blocks 24, the separation blocks 25, the contacts 26 and the second springs 27, wherein the positioning plate 21 is fixedly arranged on the inner side of the fixed disc 1 and is positioned on the far side of the fixed pin shaft 15, the alarm shell 22 is fixedly arranged on the positioning plate 21, the two moving parts 23 are movably arranged in the inner cavity of the alarm shell 22, the two protruding blocks 24 are fixedly arranged on two sides of the outer wall of the moving part 23 and are clamped in the slide ways of the alarm shell 22, the adjacent two protruding blocks 24 are electrically connected, the separation blocks 25 are fixedly arranged in the middle of the inner cavity of the alarm shell 22, the plurality of contacts 26 are respectively arranged on the inner wall of the alarm shell 22, and the second springs 27 are arranged between the separation blocks 25 and the moving parts 23.

It can be understood that the whole alarm 2 is mounted on the fixed disc 1 through the positioning plate 21, wherein two ends of the alarm 2 are respectively provided with a movable moving member 23, the outer ends of part of the moving members 23 are in an exposed state, the exposed part of the moving members 23 corresponds to the moving track position of the driving column 205, when the length of the driving end of the driving column 205 changes, in the returning process of the shoe 3, the driving end of the driving column 205 pushes the moving member 23 corresponding to the displacement position of the driving column, the moving member 23 is contracted into the inner cavity of the alarm shell 22 in a small amplitude, two lugs 24 are further arranged on the moving member 23, the lugs 24 are electrically connected, when the friction plate 5 is worn to a certain extent, the moving stroke of pushing the moving member 23 through the driving column 205 also changes until the lugs 24 move to the position of the contacts 26, the circuit communication state is processed between the contacts 26 at two sides, and at the moment, the alarm 2 sends alarm information and is displayed in an automobile instrument panel through the whole automobile controller.

In addition, a plurality of contacts 26 are arranged in the device, after the friction plate 5 is worn to different degrees, the contacts 26 at different positions are communicated through the convex blocks 24 on the moving piece 23, so that the alarm 2 can send out different alarm signals, wherein the contact 26 positioned at the most middle part of the alarm shell 22 is communicated with the alarm 2 circuit signal generating interface with the most serious alarm, and the contact is used for representing that the wear degree of the current friction plate 5 reaches the limit state.

Further, the outer end of the moving member 23 extends to the outside of the alarm housing 22 and corresponds to the movement track of the fixed column 201, so that the driving column 205 can contact with the moving member 23 on the alarm 2 after the moving member 23 moves.

Furthermore, the reinforcing plate 16 is made of a heat conducting material, so that heat generated in the braking process of the friction plate 5 can be conducted out through the reinforcing plate 16, the structural stability and the heat dissipation performance of the whole brake drum are improved, and the service life of the whole brake drum is ensured.

Further, the bending piece 204 is made of alloy memory metal material.

It will be appreciated that the alloy memory metal material has a certain position memory function, and is easy to deform when subjected to an external force, and can still maintain the current shape when the external force is removed, so the alloy memory metal material is called as a memory function.

It should be understood that the above-described specific embodiments are only for explaining the present invention and are not intended to limit the present invention. Obvious variations or modifications which extend from the spirit of the present invention are within the scope of the present invention.

Claims

1. An automotive drum brake, comprising:

a fixed disk (1);

the alarm (2) is fixedly arranged on the fixed disc (1);

the four shoe blocks (3) are respectively connected to one end of the fixed disc (1) in a rotating way through fixed pin shafts (15);

the support piece (4) is fixedly connected to the outer sides of the outer walls of the two hoofs (3);

the friction plates (5) are fixedly arranged on the outer wall of the supporting plate (4);

the fixed seat (6), the fixed seat (6) is fixedly arranged on the fixed disc (1);

the connecting shaft (7), the said connecting shaft (7) runs through the said fixed seat (6), its both ends extend to between two groups of said shoe (3) and outside of the said fixed disc (1) separately;

the driving block (8) is fixedly connected to one end of the connecting shaft (7) and is positioned between the two groups of shoe irons (3);

the roller (9) can rotate around the axis of the roller (9) and is arranged between the two hooves (3) and is tightly contacted with the outer wall of the driving block (8);

the stop mechanism is fixedly arranged between the two shoe irons (3);

a brake bottom plate (14), wherein the brake bottom plate (14) is sleeved on the outer sides of the friction plates (5);

wherein: the stop mechanism includes:

the extension seat (18) is fixedly arranged between the two hooves (3) and is positioned at the far side of the fixed pin shaft (15);

the two stop pieces (19) are integrally formed at the inner edge position of the fixed disc (1);

-a drive assembly (20), the drive assembly (20) being connected below the extension seat (18);

wherein: the drive assembly (20) comprises:

the fixing column (201) is fixedly connected below the extension seat (18);

the two sleeve pieces (202) are fixedly arranged at the upper end and the lower end of the inner cavity of the fixing column (201);

-a bending cavity (203), said bending cavity (203) being arranged at one side between two of said sleeves (202);

a bending piece (204), wherein the bending piece (204) is movably arranged in a gap between two sleeve pieces (202);

the driving column (205), the driving column (205) is fixedly penetrated through the bending sheet (204), both ends of the driving column are positioned at the outer side of the fixing column (201), and both ends of the driving column (205) are respectively a stress end and a driving end;

wherein: the alarm (2) comprises:

the positioning plate (21) is fixedly arranged on the inner side of the fixed disc (1) and is positioned on the far side of the fixed pin shaft (15);

an alarm housing (22), the alarm housing (22) being fixedly mounted on the positioning plate (21);

the moving parts (23), two moving parts (23) are movably arranged in the inner cavity of the alarm shell (22);

the two protruding blocks (24) are fixedly arranged on two sides of the outer wall of the moving piece (23) and are clamped in the slideway of the alarm shell (22), and the two adjacent protruding blocks (24) are electrically connected;

the separation block (25) is fixedly arranged in the middle of the inner cavity of the alarm shell (22);

a plurality of contacts (26), wherein the contacts (26) are respectively arranged on the inner wall of the alarm shell (22);

-a second spring (27), said second spring (27) being arranged between said separation block (25) and said mobile element (23).

2. An automotive drum brake according to claim 1, characterized in that: further comprises:

the connecting piece (10), the said connecting piece (10) is fixedly sleeved on another end of the said connecting axle (7);

a hinge support (11), wherein the hinge support (11) is rotatably connected to the other end of the connecting piece (10);

and the air cylinder (13), the air cylinder (13) is connected with the hinged support (11) through the output end of the air cylinder.

3. An automotive drum brake according to claim 1, characterized in that: the support piece (4) and the hoofs (3) are further provided with reinforcing plates (16) and reinforcing strips (17), the reinforcing plates (16) are fixedly connected to gaps between the two hoofs (3) respectively, the reinforcing plates (16) are fixedly connected with the support piece (4), and the reinforcing strips (17) are fixedly arranged on the inner wall of the support piece (4) and are perpendicular to the reinforcing plates (16).

4. An automotive drum brake according to claim 1, characterized in that: the drive assembly (20) further comprises:

a first spring (206), a plurality of the first springs (206) are arranged in the inner cavity of the fixed column (201) and positioned at the driving end side of the driving column (205);

the clamping block (207) is movably clamped in the inner cavity of the fixed column (201), and the outer wall of the clamping block (207) is in close contact with the first spring (206);

the clamping grooves (208) are formed in the outer wall of the driving column (205), and the clamping grooves (208) correspond to the clamping blocks (207) in position.

5. An automotive drum brake according to claim 1, characterized in that: the outer end of the moving part (23) extends to the outer side of the alarm shell (22) and corresponds to the movement track of the fixed column (201).

6. A car drum brake according to claim 3, characterized in that: the reinforcing plate (16) is made of a heat conductive material.

7. An automotive drum brake according to claim 1, characterized in that: the bending sheet (204) is made of alloy memory metal material.